An automatic transmission includes gear elements and clutches that selectively couple input and output shafts of the transmission to establish a desired output speed ratio. Clutch engagement is typically achieved via a controlled application of fluid pressure. The applied fluid pressure moves a clutch piston into engagement with a clutch pack. Shifting from one speed ratio to another is performed automatically by a transmission controller. At throttle tip-in, i.e., the period after a driver requests additional engine torque when engine speed is less than turbine speed but before the requested torque is delivered to the drive train, a perceptible pressure spike or bump may occur in transmission output torque as the engine momentarily freewheels. The difference in engine and turbine speed in a hydrodynamic torque converter at tip-in is proportional to the severity of the experienced bump. Bump severity can also vary with the particular design of the vehicle engine mounts which otherwise may help absorb or dampen some of the inertia of the engine.